1. Withstand the pressure from the sleeper and distribute the pressure evenly on the roadbed.
2. Fixed sleeper position, maintain track correct line and slope.
3. Eliminate the rain around and below the sleeper to prevent the soil subgrade from wet and soft deformation.
4. Increase the elasticity of the track, so that the rail after the train rolling back to the original correct position.
5. Prevent the growth of weeds in orbit.
In order to guarantee the safety of high speed railway and improve the strength of subgrade and reduce the cleaning and maintenance of the slag, the modern rail project is called "Slag-free track" by replacing the slag, sleepers and subgrade with concrete foundation. Can reduce maintenance time, maintain good quality and driving safety.